aircraft ceiling
From Glossary of Meteorology
#After U.S. weather observing practice, the ceiling classification applied when the reported ceiling value has been determined by a pilot while in flight within one and one-half nautical miles of any runway of the airport.
Aircraft ceilings may refer to vertical visibility or obscuring phenomena aloft as well as to clouds, and are designated A in aviation weather observations.
- The maximum altitude at which any given aircraft can be operated safely.
